function Distance=singleKalman(rawDis)
    %滤波系数
    A=eye(2);
    H=[1,0];
    Q=0.01*eye(2);
    R=0.01;
    %end
    % 初始化静态变量
    persistent x0 P0;
    if isempty(x0)
        x0 =zeros(2, 1); 
    end
    if isempty(P0)
        P0=eye(2);
    end
    %step_end
    %测量值导入measurement
    measurement=rawDis;
    %end
    x_pred=A*x0;% 预测下一个状态
    P_pred= A * P0 * A' + Q;% 预测误差协方差
    % 更新步骤
    K = P_pred * H' / (H * P_pred * H' + R); % 计算卡尔曼增益
    x_est = x_pred + K * (measurement - H * x_pred); % 更新状态估计
    P_est = (eye(2) - K * H) * P_pred; % 更新误差协方差
    Distance=x_est(1);
    x0=x_est;
    P0=P_est;
end